Multi-Scale Simulation Strategies for Managing Pressure Interference in Multi-Site CO2 Storage in Large Regional Aquifers

As CCS deployment accelerates across Europe, large regional aquifers like the Horda Platform are becoming central to multi-site CO2 injection strategies. Managing pressure interference between independent storage operations in such settings is a growing challenge, particularly due to complex geology and limited data sharing. This talk presents a multi-scale simulation framework that couples coarse-resolution regional models with high-resolution site-scale models. The regional model captures large-scale pressure dynamics, while the site models resolve detailed plume migration and local pressure evolution. A dynamic, noninvasive coupling strategy projects boundary conditions from regional to site models, enabling modular integration into existing workflows. The approach is implemented using OPM Flow and validated through synthetic and realistic case studies, including a coupled model of the Troll Aquifer and Smeaheia license. To enhance computational efficiency, the regional model is coarsened using vertical averaging and transmissibility upscaling techniques, reducing cell counts significantly while preserving pressure fidelity. The result is a practical and scalable solution for assessing pressure communication and dissipation across interconnected storage sites. This framework offers a valuable alternative to fully coupled simulations, supporting risk assessment and capacity planning in competitive, multi-operator environments.